An evidence-based quality improvement intervention comprising provision of physician and patient educational materials, local priority setting with leadership and providers, and local adaptation of expert-designed protocols was implemented in experimental VA primary care practices (n=9). VA control sites (n=9), matched on size and academic affiliation, received smoking cessation guideline copies. We randomly sampled, consented, screened and surveyed primary care patients at all 18 sites (n=1,941 smokers) and used computer-assisted telephone interviewing to assess sociodemographics, health status, function, and smoking behavior, attitudes and treatment experience. Post-intervention 12-month follow-up interviews were completed using the same measures (n=1,080). We used multiple imputation using hotdeck techniques and applied both enrollment and attrition weights to the patient-level data. We used weighted logistic regression to evaluate intervention effects, controlling for patient-level predictors of quit attempts and quit status (e.g., level of addiction, readiness to change, age, health).